Paper machine headbox slice opening gauge

ABSTRACT

A portable apparatus readily attachable onto the adjusting screws of a conventional paper machine headbox for producing the cross-direction profile of a paper machine headbox slice opening accurately and with sufficient repeatability so as to render the measurement dependable within the limits required for the manufacture of a high quality paper web.

MG) 28, 1974 v V I c SHELQR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4ShbBiS-Shfist l FEW F166 mil C. D. SHELOR PAPER MACHINE HEADBOX SLICEOPENING GAUGE May 28', 1974 4 Sheets-Sheet 2 Filed July 20, 1973 FIGZ y28, 1974 c. D. SHELOR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4Shoots-Shoot 5 May 28, 1974 c. DSHELOR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4Sheets-Sheet 4 United States Patent 3,813,285 PAPER MACHINE HEADBOXSLICE OPENING GAUGE Clifford D. Shelor, Tyrone, Pa., assignor toWestvaco Corporation, New York, N.Y.

Filed July 20, 1973, Ser. No. 381,270 Int. Cl. D21f 7/06 U.S. Cl.162-263 4 Claims ABSTRACT OF THE DISCLOSURE A portable apparatus readilyattachable onto the ad justing screws of a conventional paper machineheadbox for producing the cross-direction profile of a paper machineheadbox slice opening accurately and with sufficient repeatability so asto render the measurement dependable within the limits required for themanufacture of a high quality paper web.

THE BACKGROUND OF THE INVENTION 1. Field of the invention The presentinvention relates to the headbox of a paper machine and moreparticularly to a device for measuring the slice opening of a headbox.

2. Descritpion of the prior art In a fourdrinier machine, the paperstock is discharged from the headbox onto the forming wire through aslice opening, which controls the rate of flow and the amount of stockbeing deposited on the wire at any particular time. In order to producea web paper having uniform specifications across its entire width asrequired by todays paper market, the headbox slice opening must bemaintained at a constant cross-sectional area. The maintaining of aslice opening at a constant cross-sectional has been a continuingproblem in the papermaking industry for many years. The problem in thisarea, however, has been greatly amplified because of the economicdemands to run more paper per machine, per hour, and to increase thewidth of the paper web.

The slice opening of a paper machine consists of an upper lip and alower lip, each extending the entire width of the headbox. The upperlip, usually in the form of a hinge supported from the front wall of theheadbox, and the lower lip usually an extension in the form of an apronextending from the bottom of the headbox. The slice opening is'usuallypositioned over the breast roll of the fourdrinier Wire. The apronextending over the breast roll is usually thin in an effort to dischargethe slurry onto the wire without a drop off. Normal procedure for thepapermaking technician is to adjust the upper lip when the quantity ofstock flowing from the headbox onto the fourdrinier wire is increased.This, of course, is one of the methods by which the thickness of thepaper being manufactured can be increased and still maintain the speedof the wire at its normal rate.

It should be noted at this point that the requirements of maintainingthe slice opening constant across the entire width of the headbox is avery difficult specification to meet. Some of the reasons for thedifficulty are because of the great magnitude of the width. The upperand lower lip are susceptible to the structural deflection, warpage andcreep.

It has become a custom in the papermaking industry to take periodicreadings in various places of the width of the slice opening. Theterminology for such a meas urement is a cross-direction profile. Thecross-direction profile can be taken, for example, from left to right atpredetermined intervals across the width of the paper machine. Themeasurement is made of the space between the lower lip and the upperlip. The usual method. of

analysis of the measurement once'recorded is a graphic plot, Thehorizontal axis of the graph usually represents the width of the headboxand the vertical axis represents the upper lip height above the apron'at any particular point. The difiiculty in maintaining a rigid,invariable opening of the slice isa result of the flexibilityof thesteel lip, the structural deflection caused by the weight of the stockslurry in the paper machine headbox and the warpage as a result ofincrease and decreasing temperature of the paper stock.

In the past, the measurement of the slice opening has been accomplishedwith various pieces of equipment. The most notorious objection to priorart devices'is the re-' quirement for the paper technician to develop afeel for taking the reading in order to get reproducibility in readingthe points across the face of the slice opening under operatingconditions. The technician must develop a feel for maintaining aconstant pressure of the gauge against the upper lip and against thelower lip in order to get reliable readings. The constant pressure isnot easily. attainable because of the hydraulic noise andvibration inthe general area of the slice opening.

Another, less notorious, objection is that the instrument must bereadily portable in order to be moved from point-to-point to take thereading. However, in making such an instrument readily portable, thevibrations, as noted before, become an increasing obstacle to datareliability.

It is, therefore, an objective of the present invention to provide asteady, accurate, easily read display of the measurement data.

Another object of the present invention is to provide an instrument thatwill lessen the possibility of the measuring implement, namely themeasuring probe, for contacting the fourdrinier wire. It should bepointed out at this time that any contact with the wire may cause damagethereto and result in streaking the paper product.

In addition, it should be pointed out that should an instrument becomeentangled in the wire, a very costly accident would result usuallyrequiring the replacement of the fourdrinier wire. Another object of thepresent invention is to provide an apparatus for maintaining a constantpressure on the probe device during measuring the depth to which it hasbeen depressed. This, of course,

eliminates the skill of the technician and produces repeat ability indata taking.

SUMMARY OF INVENTION The present invention consists of an instrumentused in measuring the slice opening of a headbox to produce across-direction profile. It is light enough to move manually frompoint-to-point across the lip of the headbox.- In addition, it is builtto withstand the vibration inherent to measuring the slice opening of aconventional paper out at this time that inserting the probe into theslice opening is effected by the paper stock flow characteristics aroundthe probe as the stock flows from the headbox onto the wire. As pointedout before, the stock flow is flowing out of the slice opening and theprobe is being inserted into the slice opening.

Various other objects, distinctions and advantageous features of thepresent invention will become apparent from the description of thepreferred embodiment below.

. 3 BRIEF DESCRIPTION OF THE DRAWING is a side view of the slicemeasuring gauge illusillustrating the attachment of the slice measuringgauge to,

the existing adjusting rods and illustrating the, location of thepositioning plate in its normal operating mode.

FIG. 5 is a top cutaway view illustrating cross-section III-IIIillustrating the attachment of the indicating arm. 1" FIG. 6 is anisometric of the probe shaft assembly illustrating the rigid elementsthereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT -The present invention relatesto a portable apparatus for gauging the cross-directional slice openingof a paper machine headbox. Referring to FIG. 1, the structural supportof the present invention comprises a channel 17, the upper end of whichis equipped with a gauge pivot block 11, the lower end of which issupplied with a gauge glide 15. The gauge glide 15 is provided with agauge rest 16 and a positioning plate 14. Pivotally mounted from thegauge pivot block 11 is a gauge tube 12 enclosing a shaft 18. The shaft18 is coaxially positioned within the gauge tube 12 by the upper bearinghousing 9 and the lower bearing housing 13. Attached to the lower end ofthe shaft 18 is a measuring probe 19. The upper-most extremity of theshaft 18 is provided with an abutment collar 1 securely attached to theshaft by steel pin 21.

Also secured to shaft 18 is indicator bracket 5 which includes theindicator plate 6. A suitable dial indicator 27 having a 1 inchcapacity, for example, is adjustably mounted on the plate 6 forselective positionment along a line parallel with the shaft 18 axis.

Indicator arms 4, 4' are bell-crank elements having the elbows thereofpivotally secured at 63 and 65 respectively to the indicator plate 6.The long link of the upper indicator arm 4 is pivotally secured to theactuator 2, to be described subsequently, whereas the long link of thelower indic9ator arm 4 is pivotally secured to the bearing hous- Theshort links of the respective indicator arms 4, 4 are shaped to a point.Calibrated quadrants are indieia provided on the plate 6 adjacent to theindicator arm points. The quadrant calibration is merely relative andprovided only for convenient comparison of relative angular displacementof the respective arms 4, 4'.

Actuator 2 is a block element provided with a bore to slidably receivethe shaft 18 therethrough. For convenience and handling ease, handles24, 24 are secured to the actuator 2.

Assembled, the actuator 2 is resiliently biased against the abutmentcollar 1 by coil spring 28. The opposite end of spring 28 rests againstbracket 5.

. Spring 29 is disposed between bearing housing 9 and bracket 5 to biasthe unit comprising shaft 18 and bracket 5 axially upward.

The rate of spring 29 is slightly greater than that of spring 28 tosupport the shaft assembly weight at a desired neutral position forbracket 5 axially relative to hearinghousing 9.

Dimensionally, indicator arms 4, 4', springs 28 and 29 and the neutraldesign position of bracket 5 relative to housing 9 are all coordinatedso that indicator arm pointers align with an axis between pivots 64 whenin the neutral or unused condition.

) The dial indicator 27 on plate 6 is provided with indicator pointers59 and 60 on its face. Angle bracket is adjustably secured to the upperbearing housing 9such that'the plunger of the dial indicator 27 restsupon the upper lip of the angle bracket 10.

Lock 8 is used while pivoting the arm from spring 26, 26 to 53, 53'. Itspurpose is to locate the height of the probe so that ittouches neitherthe wire, the lower apron lip nor the slice lip while.being pivoted intoplace. Sliding contact could nick the slice or damage the probe.

The gauge tube 12 housing theshaft '18 is pivotally secured to the gaugepivot block 11 by journals 31 and 31.

Spring loaded button snaps 53 and 53' are pos tioned on the positioningplate 14 which is an extension to the lower gauge guide 15. Springloaded button clips 53 and 53 mate with indentations 66 and 66' locatedin the lower bearing housing 13. By the mating of spring loaded buttonclips 53 and 53' with indentations 66 and 66' respectively, themeasurement probe 19 is held in the correct position of use. Springloaded button snaps 26 and 26' are also positioned on the lowerpositioning plate 14 to the right of spring loaded button snaps 53 and53', as seen in FIG. 1. As a result of the pivoted mount provided at 62on the upper gauge pivot plate 11, the gauging apparatus, including thegauge tube 12 and shaft 18, can be conveniently held at a more desirableangle relative to the support channel 17 and other mounting structureduring the headbox attachment and removal operations. Spring loadedbutton snaps 26 and 26' are provided to secure probe 19 at awithdrawnposition relative to the slice opening. When secured to the headboxstructure, the gauge tube 12 and the shaft 18 will be pivotally swungback into the slice opening measurement position provided by springloaded button snaps 53 and 53'. Held in position by spring loaded buttonsnaps S3 and 53, the measuring probe 19 is in the precise place formeasuring the distance between the profile bar 57 and the apron plate58.

In order to hold the slice opening gauge in position on the headboxstructure for taking the measurement of the slice opening, the sliceadjusting rod screws are used for support. The adjusting rod screws areequally spaced across the face of most conventional paper machineheadboxes. The adjusting screws are supported by the front wall of thepaper machine headbox and are used to hold the lip of the slice openingin as static a position as pos-' sible, as well as providing an opening.The'customary location of the adjusting rods are parallel to each otherand equally spaced across the width of the headbox.

To accommodate mounting of the invention-to the headbox, the gauge pivot.plate 1 at the uppermost part of the instrument is equipped with springloaded button snaps 56 and 56' as can be seen in FIG. 3. 'I'he's'pringloaded button snaps 56 and 56" are positioned so as to clip onto anypair of adjusting rods. This securely attaches the upper end of theinstrument to the adjusting rods.

In order to maintain the instrument more securely, 'pins 54 and 54', 55and 55' are positioned opposite andopposed to each other respectively onthe lower gauge guide 15, as can be seen in FIG. 4. Pins 54 and 54' arelonger than 55 and 55 to enable the instrument to be placed between therods. In studying FIG. 4, it is observed that the gauge guide 15 can bemoved to the left sufiiciently enough for the pins 55 to be clear of theright-hand existing adjusting rod. At this point, the instrument can berotated clockwise sufiiciently for it to allow pin 55 to clear therighthand adjusting rod support. Of course, the reverse of this.procedure will allow positioning of the instrument between the adjustingrods. Once the pins, 54, 54', 55 and 55', and spring loaded button snaps56 and 56' are in position, the instrument is considered securelyattached to a set of adjusting rods. In conventional equipment, theadjusting rods are sufficiently long to allow the ,technican to attachthe instrument at a higher level than the actual position over theprofile bar 57 to which it must eventually be placed to efiectuate ameasurement of the slice .open-:

ing. The attaching of the mechanism at'a high level is advantageous froman operational standpoint, as well as ease of-operation and securityagainst falling into the wire. Now the instrument can be lowered againstthe profile bar 57.

The upper portion of the instrument is provided with a visual indicationof the slice opening consisting of a dial indicator 27 and a pair ofindicator arms 4 and 4'. These items can be best seen in FIG. 2. Theupper indicator arm 4 is pivotally mounted at point 63 to the indicatorbase plate 6. The extreme left end of the upper indicator arm 4 ispivotally mounted to the actuator at 64. The lower indicator arm 4' ispivotally mounted to the indicator base plate 6 at point 65. The extremeleft end of the lower indicator arm 4' is pivotally mounted to the upperbearing housing 9 at point 66.

The procedure for using the instrument is as follows: Position themechanical lock 8 so that it limits the downward movement of themeasurement probe 19 which is attached to the shaft 18 and in turn, intothe indicator bracket 5, and the indicator plate 6. The next step is torotate the probe arm, including gauge tube 12, enclosing the shaft 18about the pivot point 62 and away from the support channels 17 until itsnaps into the spring loaded button snaps 26 and 26', which are in theremote position from the support channel 17. As noted before, the sliceadjusting rods are equally spaced across the front of the conventionalmachine headbox and attached to the front wall of the headbox. Theyprovide support and adjustment for the upper lip of the slice opening.Assuming the cross-direction slice opening profile is to be taken fromthe left to the right facing the headbox, the extreme left adjusting rodwill be the firstuponwhich the instrument will be mounted. Holding theinstrument at about a 45 degree angle, with the front wall paper machineheadbox, the back of the instrument towards the front wall of theheadbox, the pins 54 and 54 can be positioned over the extreme leftadjusting rod. The instrument can then be rotated counterclockwisearound the adjusting rod until it is parallel with the front wall of thepaper machine headbox. At this point, the instrument can be pushed tothe left thereby engaging pins 55 and 55' with the slice openingadjusting rod positioned to the right of the most extreme left side ofthe slice opening. Now the top portion of the instrument can be pushedforward towards the headbox until the spring loaded button snaps 56 and56' engage the top portion of the said adjusting rod. Now the instrumentis secured to the adjusting rods and can be moved up and down parallelto the adjusting rod. Next, push the instrument down until theinstrument base block 16 seats itself on the top corner of the profilebar 57. Push down on the dial indicator bracket 5 until it rests firmlyon the stop 8 which is rotated into place at the beginning of thisprocedure. Holding the dial indicator 5 in the downward position, theprobe arm can be moved from the rear button snap positions 26 and 26' tothe frontmost button snap positions 53 and 53'. At this point, releasethe dial indicator bracket 5 allowing the probe 19 to come up until itcontacts the bottom edge of the slice profile bar 57. Spring 29 isbiased against the indicator bracket 5 such that a predetermined amountof pressure is applied through the shaft 18 to the probe 19, therebyholding the probe against the upper face of the profile bar 57. Thisstep should be repeated gently two or more times to be sure that arepetitive reading can be taken on the dial indicator 27. When repeatingthese steps, the dial indicator should be watched to see that thepointer 60 comes to rest at the same point after each depression andrelease of the indicator bracket 5.

Now, set the dial indicator to a zero reading in order to get a relativereading of the slice opening. Turn the outside rim of the dial indicator27 until the large pointer 60 is at 0. Note, the unit was set up with asmall, initial preload on the dial indicator to prevent unmeasured endplay of the indicator follower button. Depending on how 6. theinstrument is manufactured, the usual preload depression isapproximately 0.10 inch, which means that the small point of 59 shouldread approximately 0.1 inches. If it doesnt, readjust the dial indicatorpositioned within its slotted mounting on the indicator plate 6. Next,rotate the stop 8 so it will no longer limit the downward move-. ment ofthe probe 19, its shaft 18 and the dial indicator bracket 5. Next, gripthe black plastic handles 24, 24' respectively, and apply a smoothuniform force downward while watching the indicator arms 4 and 4 whichare located just to the right of the dial indicator 27. As the movementis continued downward, the indicator arms 4 and 4' will moveapproximately together. When the bottom indicator 4' stops moving, thisindicates that the probe 19 has contacted the bottom of the apron lip58. Now, continue pushing until the top point of arm 4 has moved aboutone division as indicated on the indicator plate 6 from the restposition for the lower pointer arm 4'. The separation between theindicator arms 4 and 4', as noted on the indicator plate 6, is directlyproportioned to the amount of pressure that is being applied to theprobe 19 through the shaft 18, the spring 28, and the actuator 2. Atthis position, read the dial indicator 27. In order to read the dialindicator 27, the small pointer 59 must be read first and add to it thelarge pointer 60 reading. For example, the small pointer 59 wouldpossibly be located between 0.5 and 0.6 inches so the reading is 0.5.The larger pointer will give the fraction that should be added onto thesmall pointer reading of 0.5. Next, read the large pointer. Assuming thelarge pointer reads .050, this gives a total overall reading of 0.550.The thickness of the probe must also be considered in the preferredembodiment of the present invention. The probe 19 may, for example, beexactly 0.400 inches, therefore, we must add this amount to the readingof the dial indicator. It should be noted at this time that we startedwith a reading on the small pointer of 0.1 in order to provide a preloadon the dial indicator follower button. Therefore, the actual sliceopening would be 0.850, the indicator 27 reading, plus 0.400,the-thickness of the probe 19 minus 0.1 inch preload deflection.

After taking a reading, place the stop block 8 back into place. Pushdown on the dial indicator bracket 5 until it contacts the stop 8.Holding the bracket 5 against the stop 8, snap the probe 19 back out ofthe slice opening 61 and into the rear spring loaded button snaps 26 and26'. At this point, release the indicator bracket 5. Lift the gaugeseveral inches off the profile bar 57. Pull the spring loaded buttonsnaps S6 and 56' from around the adjusting rods away from the headbox.Move the instrument to its extreme left, disengaging the pins 55 and 55.Turn the instrument at a 45 angle with regard to the front face of theheadbox and disengage the pins 54 and 54' from around the adjustingrods.

This reading is the first point on the cross-direction profile from leftto right on a conventional paper machine headbox. The instrument shouldnow be placed in the space provided between the second and thirdadjusting rods and the procedure above repeated. Next, the procedureshould be between adjusting rods 3 and 4, and 4 and 5, and 5 and 6, etc.across the entire width of the paper machine headbox. The points can beplotted on a graph, the abscissa of which represents the width of theheadbox and the ordinate representing the height that the slice openingis located above the apron plate. A visual picture of the width of theslice opening above the base plate will be projected by graphs of thecross-direction profile.

Because many varying and different embodiments may be made within thescope of the inventive concept herein taught, and because manymodifications may be made in the embodiments herein detailed inaccordance with the description requirements of the law, it is to beunderstood that the details herein are to be interpreted as illustrativecrank elements, said bell-crank elements pivotally seand not in alimiting sense. cured to said pivot support proximate of the bell-crankI claim: elbow, one link of a first bell-crank element being pivot- 1.\An apparatus for measuring the distance between an ally secured to saidcollar element and one link of the upper slice lip and a lower slice lipof a paper machine other bell-crank element being pivotally secured tosaid headbox comprising: tubular element.

a frame structure releasably secured to headbox struc- 3. Apparatus asdescribed by claim 1 wherein said first ture; resilient means has agreater spring rate than said second a tubular element secured to saidframe structure havresilient means.

ing a rod element disposed axially therethrough, the 10 4. Apparatus asdescribed by claim 2 wherein said bellends of said rod projectingaxially beyond respective crank elements each include a pointer portionand said ends of said tubular elements; first and second resilient meansare provided with relative an abutment element secured to one end ofsaid rod Spring rates whereby a relative force bias on said probeelement; means against said lower slice lip may be determined by abracket element secured to said rod element between 5 mparing therelative displacement position of said first id abut nt l t d arespgcfive d of id bell-crank pointer portion to the relativedisplacement pot bu1 l t; sition of said second bell-crank pointerportion when a a collar element disposed about said rod element anddisplacement force effective to engage Said Probe means i n free l i thid 11 element with said lower slice lip is applied to said collarelement. sitioned between said abutment element and said I b k l IReferences Cited first resilient means compressively disposed betweenUNITED STATES PATENTS said bracket element and said respective tubular3,575,799 4/1971 Gedemer at a! element 3 487 686 1/1970 s 1 secondresilient means compressively disposed between 3399565 9/1968 omon 162263 X chmaeng l62263 X said bracket element and said collar element; 2338 001 12/1943 L displacement measuring means secured between said2523551 3 33-170 backet element and said tubular element; and pro emeans secured to the other end of said rod elev ment for positionmentbetween said upper and lower S- L BASHORE Primary Examiner slice lip andbeing selectively movably therebetween DKANDREA Assistant Examinerwhereby the distance between said upper and lower slice lip may bederived irom said measuring means. 2. Apparatus as described by claim 1wherein said 33-170, 181 R; 162-198 bracket element comprises pivotsupports for two bell- 35 9/1950 Bauer et a]. a 33-l72 R

